The Center on Budget and Policy Priorities has made some splashes with this graph. I find this strangely unconvincing as a policy argument for anything.
For starters, the 0.7% of GDP that it covers only matches the shortfall for a brief period, at least according to the Social Security Trustees report. By the middle-to-late twenties, the shortfall is more than twice the amount of the Bush tax cuts on the rich. Even if we hadn't already (hopefully) earmarked this money for something else, this would be at best a stopgap measure; the program would rapidly begin putting more pressure on the budge
But I can't even make those numbers add up over the short term. By the admittedly ham fisted method of dividing the roughly $700 billion the CBO said that extending the Bush tax cuts for the rich would cost, by the $190 trillion worth of GDP that the CBO projects over the next ten years, I get 0.36% of GDP, not 0.7%. The CBO's numbers don't seem to be increasing much beyond the rate of inflation towards the end of the forecast period, so I find it hard to reconcile their numbers with the CBPPs even by extending out the forecast period. And for all my skepticism of the accuracy of CBO forecasts, I am apt to trust them over a think tank with a decided ideological tilt (in either direction).